Ok its seems that you need an IO ROM for this. In the IO ROM there is a function TCAT$. For example my 75C with an IO ROM it auto assigns my diskette drive to be :M1 on the command line I enter F$=TCAT$(':M1',2) @ DISP F$ and it displays the file name of the second file on the diskette in the drive. This should work the same way for a tape drive, I would try it but since getting a diskette drive I don't use my tape drives anymore and have cleared all of my tapes.

If you don't have an IO ROM there may be a LEX file available that provides this function, or you could read and parse the raw directory block from the tape.

I don't know sorry, I said there MAY be one, not that I knew of one. I would like to catalog all the LEX files on the various exchange diskettes made available on this site, but so far I have not got around to it, it is easy using the HELP LEX to find the keywords, but sometimes figuring out the syntax to go with the keywords is difficult.